November 2008 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Shared Group Timeslots ] Date Submitted: [ 10 November, 2008 ] Source: [ Michael Bahr, Norbert Vicari, Ludwig Winkel ] Company [ Siemens AG ] Address [ Otto-Hahn-Ring 6, München, Germany ] Voice:[ +49-89-636-49926 ], FAX: [ +49-89-636-51115 ], E-Mail:[ bahr at siemens. com ] Re: [response to Call for Proposals doc 15-08/0373r1] Abstract: [ Further specification of Shared Group Timeslots from Proposal to IEEE 802.15.4e for wireless sensor/actuator networks applicable for factory automation.] Purpose: [amending 802.15.4-2006 for matching the requirements for factory automation] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. M. Bahr, N. Vicari, L. Winkel, Siemens AG

Shared Group Timeslots November 2008 Shared Group Timeslots Michael Bahr (Siemens AG) Norbert Vicari (Siemens AG) Ludwig Winkel (Siemens AG) M. Bahr, N. Vicari, L. Winkel, Siemens AG

General Concept IEEE 802.15.4 PHY frames Time Division Multiple Access November 2008 General Concept IEEE 802.15.4 PHY frames Time Division Multiple Access superframe with timeslots of fixed length shared group timeslots with CSMA addressing based on timeslot location or short address (1 octet) modified MAC frame Roaming capability M. Bahr, N. Vicari, L. Winkel, Siemens AG

Shared Group Timeslots November 2008 Shared Group Timeslots one or more continuous timeslots concatenated to a shared group timeslot more than one device per timeslot carrier sense multiple access within shared group timeslot all timeslots in single shared group timeslot  network with carrier sense multiple access mixture between fixed, deterministic timeslots and shared group timeslots possible M. Bahr, N. Vicari, L. Winkel, Siemens AG

General Structure of Shared Group Timeslot November 2008 General Structure of Shared Group Timeslot tSlotStart – tSlotTxOwner: sensor node that owns the slot has exclusive access tSlotTxOwner – tSlotTxGW: if slot is unused, all sensor nodes can use this slot with modified CSMA/CA access (e.g. retransmissions, management devices) tSlotTxGW – tSlotEnd: if slot is still unused, gateway can use this slot for announcing the network M. Bahr, N. Vicari, L. Winkel, Siemens AG

November 2008 Usage by Slot Owner only slot owner (exactly 1 sensor/actuator) allowed to send before tSlotTxOwner contention free access acknowledgement via: group acknowledgement acknowledged mode (not shown on this slide) unacknowledged mode M. Bahr, N. Vicari, L. Winkel, Siemens AG

November 2008 Usage by Any Sensor any sensor/actuator can use the slot if not used by slot owner contention-based access (modified CSMA/CA) data frame has to fit into shared group timeslot acknowledgement via: acknowledged mode unacknowledge mode (not shown) M. Bahr, N. Vicari, L. Winkel, Siemens AG

November 2008 Usage by Gateway if slot is still unused after tSlotTxGW, gateway can send network announcement used for detection of network activity by new sensors contention free access usage of this mechanism is optional M. Bahr, N. Vicari, L. Winkel, Siemens AG

Acknowledgement of Transmission November 2008 Acknowledgement of Transmission Group Acknowledgement only possible for dedicated usage by slot owner Acknowledged Mode gateway (actuator) sends acknowledgement frame right after successfully received data frame from sensor/actuator (gateway) necessary for contention-based transmissions requires explicit addresses  1 byte addresses are sufficient for 250 sensors requires 2 additional Rx/Tx-switches Unacknowledged Mode always possible M. Bahr, N. Vicari, L. Winkel, Siemens AG

Summary further specification of shared group timeslots November 2008 Summary further specification of shared group timeslots 3 specific usage opportunities dedicated access by slot owner before tSlotTxOwner contention-based access by all sensors after tSlotTxOwner if slot available (modified CSMA/CA) network announcement by gateway after tSlotTxGW if slot is still available different acknowledgment schemes group acknowledgement for dedicated access by slot owner acknowledged mode for contention-based access by any sensor unacknowledged mode short addresses for acknowledged mode with length of 1 (one) octet M. Bahr, N. Vicari, L. Winkel, Siemens AG

References 15-08/0503r0 Preliminary Proposal for Factory Automation November 2008 References 15-08/0503r0 Preliminary Proposal for Factory Automation presentation of preliminary proposal for factory automation at July 08 IEEE 802.15.4e meeting 15-08/0571r1 Proposal for Factory Automation presentation of proposal for factory automation at September 08 IEEE 802.15.4e meeting 15-08/0572r0 Proposal for Factory Automation text of proposal for factory automation M. Bahr, N. Vicari, L. Winkel, Siemens AG